package com.hmdp.service.impl;

import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.ShopType;
import com.hmdp.mapper.ShopTypeMapper;
import com.hmdp.service.IShopTypeService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;
import java.util.concurrent.TimeUnit;

import static com.hmdp.utils.RedisConstants.CACHE_SHOP_TTL;
import static com.hmdp.utils.RedisConstants.CACHE_SHOP_TYPE_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopTypeServiceImpl extends ServiceImpl<ShopTypeMapper, ShopType> implements IShopTypeService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    
    @Override
    public Result shopTypeList() {
        String key = CACHE_SHOP_TYPE_KEY + "list";
//        1.先在缓存中查询
        String shopTypeJson= stringRedisTemplate.opsForValue().get(key);
//        2.判断是否为空
        if (StrUtil.isNotBlank(shopTypeJson)) {
            //        3.存在，直接返回
            List<ShopType> shopTypes = JSONUtil.toList(shopTypeJson, ShopType.class);
            return Result.ok(shopTypes);
        }
//        4.缓存中不存在，查询数据库
        List<ShopType> shopTypes = query().orderByAsc("sort").list();
//        5.判断是否为空
        if (shopTypes==null) {
            return Result.fail("分类不存在！");
        }
//        6.保存到缓存中
        stringRedisTemplate.opsForValue().set(key,JSONUtil.toJsonStr(shopTypes),CACHE_SHOP_TTL, TimeUnit.MINUTES);
//        7.返回
        return Result.ok(shopTypes);
    }
}
